Conventional high-value, fixed facilities, such as facilities that store nuclear materials or maximum security prisons, typically include security systems that allow for detection and response to a perceived threat. For example, typical high value fixed facilities include security systems that detect potential ground-based intrusions (e.g., cars or trucks) that occur in the vicinity of the facility. In response to detecting such an intrusion, the security system generates a warning thereby allowing the facility's security force to provide an appropriate ground-based response to the perceived intrusion.